1. Field of Invention
This invention relates to sheet transporting devices within an image forming apparatus.
2. Description of Related Art
Various systems designed for transporting a sheet in a predetermined path have a number of devices to advance the sheet along the predetermined path within an image forming apparatus. Examples of such sheet transporting devices include sheet grippers, drive rolls with idlers and sheet guides. The sheet transporting devices are fixed at various stationary locations along the predetermined path. Consequently, the stationary sheet transporting devices act on the sheet as the sheet is transported through each sheet transporting device. Some systems have multiple sheet transporting devices that move in and out of operative positions, to provide operator access.
Conventionally, previous sheet transporting devices for a particular application have been integrated into a single, unitary assembly.
One of the advantages of the idler mounting tie-bar assembly is that it locates the drive components of a sheet transporting device in precision frame assemblies that relate to one another through collinear alignment features. The idler mounting tie-bar assembly controls the relationship of the drive roll, the idler roll and the paper guides to minimize variations, which affect paper handling. Additionally the paper guide is able to attach and detach to the precision frame assembly so that the paper guide can be replaced when required.
Another advantage of the invention is that the idler mounting tie-bar assembly allows individual components, which tend to wear after use in an image forming apparatus, of the various sheet transporting devices to be replaced independently. Furthermore, the individual components may be separated and removed from the idler mounting tie-bar assembly.
Previously, if any one of the sheet transporting devices, such as a sheet guide, the baffle surface, or the like required replacing for any of a variety of reasons, it was necessary to replace the entire assembly, including those sheet transporting devices which were operating adequately. Unfortunately, replacing the entire assembly, if a single paper guide requires replacing, inefficiently discards usable materials and is unnecessarily expensive. Thus, it would be desirable to provide a sheet transporting device assembly that allows individual components of the devices to be independently and detachably mounted or combined together so that individual components of the various sheet transporting devices could be replaced without requiring replacement of the entire assembly.
One exemplary embodiment of the tie-bar idler assembly according to this invention is a tie bar idler roller assembly. This invention separately provides a tie bar idler roller assembly that allows the user to access the area in between the idler rollers and drive rollers.
The idler tie-bar assembly has a main frame portion having a plurality of grooves, protrusions, openings and bends located within the frame weldment, also referred to as the outer frame as referred to in this application. The idler tie-bar assembly further includes a plurality of openings, each of which is able to receive at least one idler roll. Each of the idler rolls are connected to the idler tie-bar assembly by at least one spring member. The movement of each of the idler rolls is limited in the corresponding opening by a slot located between the two members. The idler roller is able to move vertically along the slot portion. The spring members arc located on each end of a shaft which runs through the middle of the idler roller. The springs pull the idler roll towards the opening on the frame weldment of the idler mounting tie bar assembly with a controlled force.
The idler tie-bar assembly also has two end plates located on each end of the frame assembly that aligns the frame to a main support structure. The endplates have locating features. On a pivoting assembly, a pivot device connect the end plates to the main structure. On the opposing end of the end plates, a locking member locks the tie bar idler roller holder assembly in an operative position relative to the main structure. The pivot device allows the tie bar idler roller holder assembly to rotate with respect to the main structure to allow the tie bar idler roller holder assembly into an open position.
There are two styles of access assemblies, that usually pivot. The first pivots along the process direction, the second pivots 90 degrees to process direction. Both of these assemblies may use the same alignment principals, to maintain precision location of the components of the apparatus.
These and other features and advantages of the systems and methods of this invention are described in or are apparent from the following detailed description of the various exemplary embodiments.